The present invention generally relates to methods and devices for transporting a multiplicity of wire spools and other elongate stock about a work site. More specifically, the present invention discloses a transport apparatus supporting one or more spools of flexible elongate material, so that each spool may be unrolled in the same direction and gathered in a bundle without deforming the transport system by their weight. The invention may be employed wherever it is desirable to dispense generally similar reeled materials, which may differ in certain aspects, such as dimensions, color, minor internal or external construction, and the like.
Construction electricians must typically have on hand many different types of electrical cables for a construction project. These types of cables may differ in many aspects. For example, different wire gauges are typically employed throughout a building. In large commercial, institutional, and industrial projects served by multiphase electrical supply systems, the various phases and neutral conductors are usually distinguished by color coding of the insulating jacket. Some applications require stranded conductors, while others require solid, single filament conductors. Therefore, a wide variety of electrical cables area are typically required in each construction project.
It is preferred to work with spools having a significant length of cable in order to avoid frequent depletion of a spool. Many electricians prefer to work with multiple spools each containing as much as 2,500 feet of cable. The cables are deployed to allow each cable to be unrolled in the same direction and optionally bundled together as a single wire run. As wire gauge increases, the various spools become correspondingly heavy. However, the force required pull the cables in the same direction may be exerted in a perpendicular direction against the upright standards that support the wire spools, so that the upright standards may be deformed longitudinally in the direction of pull. Eventually such strain may permanently bend the upright standards or cause them to fail. Furthermore, the inertia of the heavy wire spools may have the same effect when the wire cart is pushed about the work area.
The prior art has proposed carriages adapted to carry spools of wire and to make dispensing easy and practical. For example, U.S. Pat. No. 5,188,308, issued to Tussing on Feb. 23, 1993, describes a wire cart adapted to store a plurality of wire spools. The cart has a plurality of vertical posts from which branches project laterally. The spools are supported on the branches. Tussing discloses that the posts are vertically fixed in position on the cart. The posts rotate on the cart between a first position enabling easy loading of a spool onto a branch and a second position wherein wire is paid out in the same direction from which the spools are loaded. The supporting branches or rods of the present invention latch into place in the second position.
U.S. Pat. No. 5,316,232, issued to Lambert, Jr., on May 31, 1994, also describes a wire dispensing cart which carries spools of wire. The spools are supported on fixed horizontal rods on vertical supports. Rods supporting the spools rotate to enable easy loading of spools onto the rods.
A wire dispenser seen in U.S. Pat. No. 5,285,981, issued to Pavelka on Feb. 15, 1994, supports spools in one position. The device of Pavelka lacks ability to shift between first and second positions and to latch in one of the positions, as seen in the present invention.
U.S. Pat. No. 4,605,237, issued to Torgrimson on Aug. 12, 1986, describes a two wheeled wire dispensing carriage wherein spools are supported between the two wheels, which are quite large. The rods supporting the spools are fixed in position generally parallel to the axle. Torgrimson's device lacks the ability to shift between first and second positions, and to latch in one of the positions.
The inventor's prior patent (U.S. Pat. No. 6,422,504) discloses a wire spool cart for the transport of wire spools about a work site and dispensing of wire from the wire spools. The wire spools are supported on an angled spool rod support 30 that is in turn supported at its ends by a front post 24 and a rear post 28, which are oriented vertically. However, the front and rear posts may be subject to racking and deformation from their vertical position when the cart is urged into motion. Furthermore, the angled spool rod support may bow in the middle if it is weighted down by too heavy a spool load. The angled spool rod support enhances the ability of the wire spool cart to dispense wire simultaneously and is not directed to provide resistance to racking or supporting heavy loads.
When the number of spools becomes large, the weight of the spools on vertical supports may be significant so as to deform the supports when the cart is moved or when wire is pulled out from the spools against the resistance of the spools and posts. For example, commercial and industrial applications employ multi-wire cable bundles clad in various sheathing for different uses in buildings. Different types of wire bundles are frequently identified by their sheathing material, as, for example, MC (metal clad) cable, MI (mineral insulated) cable and AC (armored cable) among others. Use of these cladding materials along with wires having gauges of 12 and below result in wire spools that are excessively heavy for moving about the work site. Such wire spools may typically weigh between 100 lbs to 150 lbs, with average reel sizes of 24″ in diameter and 14″ in width. The larger spool sizes can typically go up to 24″ wide and 30″ in diameter with corresponding weight depending upon the type of cable and the cable length.
When spool sizes reach these weights and dimensions, a jack stand may be typically employed to support the spool for extraction of the cable held thereon. Such stands feature a horizontal axle that is inserted through the spool, whereupon the stand is tilted to lift the spool off the floor surface to allow it to rotate on the axle to dispense cable. Because of the bulk and weight of such spools, a single stand is employed for each spool. If the spools are to be moved to another location, they must be individually transported one by one to the new location and then reinstalled on the jack stand again.
As can be seen, there is a need for a transport system that may carry a plurality of spools simultaneously for a given size and that will be sturdy enough to resist racking force caused by inertia of the spools against the transport system when the transport system is urged into motion.